I shall apply the term "mental world" to the still larger globe of mental matter in the midst of which our physical earth exists.

When we come to the still higher globes we have spheres large enough to touch the corresponding spheres of other planets in the system, though their matter also is just as much about us here on the surface of the solid earth as that of the others.
All these globes of finer matter are a part of us, and are all revolving round the sun with their visible part.

The student will do well to accustom himself to think of our earth as the whole of this mass of interpenetrating worlds--not only the comparatively small physical ball in the centre of it..